I agree with most of it, though the point about academia is a bit contrived.

True, there is a lot of negative selection before you get a cushy job the usual way, but you can certainly bypass quite a few obstacles if you are exceptionally good. For example, solve any of the open problems in math or physics, post a preprint on arxiv.org (well, you may need someone to vouch for you, but that's not really an issue) and you are all set.

Unfortunately, I cannot recall a single discovery in physics in the last half a century that was not made by someone who jumped through the usual hoops. I have met, however, an occasional person who learned grad school-level stuff on their own, but they did not manage to go any farther. My suspicion is therefore that all that negative selection in science, while annoying, does not do a lot of harm compared to potential alternatives. While it filters out some good people, it probably does not reject the very best, otherwise we would see an occasional example of someone making a significant discovery outside academia.